Push-pull selector switch with key locking arrangement



May 16, 1950 aw. JOHNSON PUSH-PULL SELECTOR SWITCH WITH KEY LOCKING ARRANGEMENT Filed July 6, 1948 3 Sheets-Sheet &

INVENTOR.

JOHNSON 3 DAVID W.

May 16, 1950 D. w. JOHNSON PUSH-PULL SELECTOR SWITCH WITH KEY LOCKING ARRANGEMENT Filed July 6, 1948 5 Sheets-Sheet 2 [ac/(0 r0 PREVENT 4'6 54: IQOTAT/O/V a? Fuzz/Ms;

l0 Pas/0N6 ALLOWED.

PUSH-PULL SELECTOR swrrca wrm KEY LOCKING ARRANGEMENT Filed July 6, 1948 May 16, 1950 D. w. JOHNSON 3 Sheets-Sheet 3 INVENTOR. DAVlD w. JOHNSON 5 11.219 aiZarrzeys I Patented May 16, 1950 PUSH-PULL SELECTOR SWITCH WITH KEY LOCKING ARRANGEMENT David W. Johnson, New Britain, Conn., assignor to'The Arrow-Bart dc Hegeman Electric Company, llartlord, Conn.,

nectiout a corporation of Con- Application July 6, 1948, Serial Nae-1.15s

This invention relates to push-pull selector switches of the sort illustrated in my copending application, SerialNo. 576,270, filed February 5,

1945, entitled Push-pull selector switch, now Pat-- ent 2,451,224, issued October 12, 1948.

In such switches there is provided a mechanism whereby the handle of the switch may be grasped and pushed or pulled to causeoperation of so-called control contacts. The control contacts are located in one section of the switch, preferably. In other sections of the switch there are located selector contacts which are operated by rotation of the switch handle; in another section of the switch there is an interlocking arrangement whereby the handle can be rotated only when the switch shaft has been moved to a certain axial position.

Although the invention which I am about to describe is applicable to the structure above-mentioned, it is also applicable equally to variations in that type of structure and hence it will be understood that the present invention is not limited to the particular type of push-pull switch in connection with which the present invention will be described. I

On some occasions it is desirable to be able to lock the switch in certain positions so that the operator of a machine or other device which the switch controls shall be permitted only limited ability to operate the switch or perhaps not be permitted to operate it at all after the switch has once been set in a given position. Thus, the ability to lock the switch in certain positions finds particular utility in connection with machine tool applications.

Thus, it is an object of my invention to provide locking means whereby a push-pull selector 1! Claims.

Other objects and advantages of the invention will appear as it is described in connection with the accompanying drawings.

In the drawings:

Figure l is a side elevation view of an electric switching device embodying the invention;

Figure 2 is a plan view of the device-in Figure 1,

the device being shown in unlocked position by switch of the type above mentioned, or similar 1 switches, may be locked in a certain position.

Another object of my invention is to pro- 'vide a locking means of the sort mentioned wherein the switch may be operated to a limited extent when locked, such, for example, as in an axial direction but not in a rotary direction.

Another object of 'my invention is to provide a locking means for a switch of the aforementioned means will'not entail a large increase in the cost of production.

dotted lines:

Figure 3 is a transverse section view taken along line 8-3 of Figure 1 looking in the direction oi the arrows;

Figure 4 is a broken longitudinal section view taken along line 44 of Figure 3 looking in the direction of the arrows;

Figure 5 is a side elevation view partly broken away, of the parts shown in Figure 4 but with the parts locked into complete immobility;

Figure 6 is a section view similar to Figure 3 partly broken away, of the parts illustrated in Figure 3;

Figure 7 is a perspective view of the switch shaft and locking parts carried thereby in association with the key operated locking elements. The parts are in unlocked position.

Figure 8 is a fragmentary perspective view from the same viewpoint as Figure 7, of some of the parts shown in Figure 7. The parts are in the same position as in Figures 3 and 4.

As illustrated, the invention is mounted upon a plate In which may in turn be mounted upon a machine or a panel; or the machine and panel may be formed in the same manner as the plate so that the switch and locking means may be mounted thereon directly.

may control the circuit to power lines and is I designated as the control section.

The sections B each contain fixed and movable leaf spring contacts, the movable contacts being operated by a cam on the switch spindle when the spindle rotates. The sections B are called selector sections and may be employed for selecting different circuits. Since the form of the cam, fixed and movable contacts and selector sections generally are as disclosed in my 3 priorapplicatimtheyarenotiilustratedindetailherein.

The section C is termed the interlocking section. It houses a lock member I00. The lock member may comprise a plate stamped from sheet materal with a series of arcuate concentrically located fingers I02 bent to extend parallel to the axis of the operating shaft 20. The operating shaft 20 passes through all of the aforementioned sections and out through the end of the switch having thereon a handle 22 by means of which the operating shaft may be pushed or pulled or turned.

Upon the operating shaft there is affixed a fabricated key member 90 by means of a pin 01. Wings -w extend radially from the fabricated key and their end portion !0:: extend through the slots between the fingers I02.

A spring (not shown) located in the control section normally maintains the operating shaft in an intermediate position to locate the extension 06-x of the key member within the outer end of the slots between the fingers I02 of the locking member. Thus, turning of the operating shaft is prevented under normal conditions.

This locking condition is maintained also when the shaft is pulled for the reason in position of Figure 4 (the normal intermediate position) the extension 06-1: is not fully down in the slot between the fingers l02. However, when the shaft is pulled the extension 96-:1: will come down to the bottom of the slot thus maintaining the locking engagement.

When the shaft is pushed from the neutral or normal position the extension 06-3: will move out from whichever of the slots in which it has been located, so that it is then possible to rotate the shaft.

To limit the rotation of the shaft to a predetermined are or number of positions, a rib or stop I i 2 extending parallel to theoperating shaft axis and bent up from a stop plate H0 is provided in position to be engaged by the ends 96-a: of the fabricated key member.

All of the foregoing structure is described in more detail and specifically claimed in my prior copending application 576,270.

The improvements about to be described are particularly adaptable to the type of structure just referred to.

In order to lock the shaft against all movement, a cup-shaped sheet metal locking member 30 is afllxed to the shaft 20 between the handle 22 and the locking member I00. Locking member 30 is of circular shape and has a flange 32 which is cylindrical in shape and has cut into it at spaced intervals slots 34. Pivotally mounted on the underside of the mounting plate [0 is a locking lever 40 which may conveniently be stamped from sheet metal. The locking lever 40 is pivotally mounted at its mid-portion upon a pivot pin 42 which in turn is mounted in the mount ng plate l0. One end of the locking lever 40 is recessed to provide a pair of spaced parallel arms 43, 44. Between the arms 43, 44 there is an eccentric 46 whose diameter is approximately equal to the spacing of the inside surfaces of the arms 43, 44. The eccentric 46 is pivotally mounted upon a rotatable key-receiving member 52 which may be turned within an opening in the mounting plate i0.

The key receiver 52 has an irregular slot therein for the reception of a key 54; thus turning of the key will cause rotation of the eccentric which 4 inturnwillcausethelockingleverlltopivot about its pivot 42.

The opposite end of the locking lever 40 is bent at right-angles to the main body .of the lever providingalughavingamainportlon andastep 40 whose height is less than the height of the portion 40.

If the parts are assumed to have the position illustrated in Fig. 7. the handle 22 and operating shaft 20 may be pushed carrying with them the locking disc or member 30. When pushed sumciently the key may be turned causing rotation of the eccentric 40 and pivoting of the locking lever 40. In this way the lug 40 may enter one or another of the slots 34 and the end surface 50 of the main body of the lug 48 will move over the inside surface of the locking member 30 into the position illustrated in Figs. 5 and 6.

If at this time the operator removes his hand from the handle 22, the handle and operating shaft cannot resume their normal position nor can they be pulled because the end surface 00 of the lug 48 prevents such further pulling. Hence, the parts are locked axially into the position into which they have been pushed. Furthermore, in said position the handle and operating shaft may not be rotated because the side surfaces of the slot 34 engage the lug 48. I

Upon rotating the key and the eccentric 40 from the position of Fig. 6 the locking lever 40 will be reversely pivotted about its pivot 42 to cause unlocking.

The first result of the unlocking movement of the locking lever 40 is initiated by the key is movement of the lug portion 48 out of the slot 34. When that happens, the disengagement of the end 50 from the disc portion or inner surface of the locking member 30 will allow the shaft 20 to be pulled outward, or to move outward under the urge of the spring (not shown) which, as

aforementioned, is located in the control section. This outward movement will stop when the shaft 20 comes to intermediate or normal position.

However, when only the lug portion 48 has moved out of the slot 34, the step portion 49 will still remain within the slot. Under that condition the step 49 will overlie the disc portion of the locking member 30. Such a condition is illustrated best in Figs. 4 and 8 (see also Figs. 2 and 3). The handle and shaft may be pushed from that intermediate position to another position which may be an off-position if the invention is applied to the form of switch shown in my copending application, Serial No. 576,270. It will be understood, however, that such pushed position need not-be an off position because the invention is not limited in that respect.

It will be observed that with the locking lever 40 in the position illustrated in Figs. 2, 3, 4 and 8. the handle and operating shaft may not be rotated regardless of the location of the shaft in the position shown or in a pushed position. Rotation is prevented by the engagement of the step portion 49 with the side of the slot 34.

From the foregoing it follows that only when the locking lever 40 is rotated by the key and eccentric 46 to the position of Fig. 7 that the shaft and handle may be either pushed or pulled from the intermediate position.

Due however to the primary locking member I00 and the engagement therewith of the extensions 96 in the neutral and in the pulled position of the handle, as apparent from the drawings. and as'described in my co-pending application 576,270, it is only possible to rotate the handle and operating shaft when the handle and shaft have been pushed.- Such pushing and subsequent rotation with the present invention can only be accomplished when the locking lever 40 is entirely disengaged from the secondary locking member 30 because when the lever 4|! is partially engaged as illustrated in Figs. 2, 3, 4 and 8, rotation after pushing is prohibited by engagement of the lug 48 with the sides of the slot 34.

Many modifications within the scope of the invention will occur to those skilled in the art and therefore it is not limited to the specific embodiments shown.

What I claim is:

1. In a switch, a shaft movable to operate different sets of contacts by movement axially to and fro from an intermediate position and also rotatively, mounting means for said shaft, looking means turnable about a fixed pivot, a locking member affixed to said shaft interengageable by said locking means, means to turn said locking means into engagement with said locking member,-the interengagement of said locking means and locking member preventing turning of said shaft regardless of the axial position of the shaft.

2. In a switch as claimed in claim 1 wherein said locking means and locking member may occupy two different engaging positions in one of which said shaft is entirely immobilized.

3., In a switch as claimed in claim 2 wherein in the other of said two positions the shaft may be moved axially in one direction only from an intermediate position.-- a

4. In a switch as claimed in claim 1 wherein said locking means and locking member are formed topermit movement axially of said shaft in one direction only from an intermediate position when said locking means and member are in one engaging position.

5. In a switch as claimed in claim 4 wherein the locking means comprises a lever having a stepped lug which is engageable either wholly or partially with the locking member on said shaft.

6. In a switch, a shaft movable to operate different sets of contacts by movement axially to and fro from an intermediate position and also rotatively, mounting means for said shaft, locking means turnable about a fixed pivot, a looking member affixed to said shaft interengageable by said locking means. means to turn said locking means into engagement with said locking member, the interengagement of said locking means and locking member preventing turning of said shaft regardless of the axial position of the shaft. said locking means and locking member being engageable in two different positions in one of which said shafts is entirely immobilized in an axial position other than the intermediate axial position.

I. A switch as claimed in claim 6 wherein the locking means comprises a lever having a stepped ing which has its end face in engagement with meeting member in said one immobilized po- 8. In a selector switch, a shaft movable rotatively and axially to operate different contacts,

said shaft being movable axially from an intermediate into pushed and pulled positions, means upon which said shaft is mounted, interfitting means on said shaft and said mounting means preventing rotation of said shaft under certain conditions, said interfitting means being freed by axial movement of said shaft in one direction from intermediate position, said shaft being turnable when said interfitting means are freed, in combination with locking means turnable about a fixed pivot, a locking member affixed to said shait interengageable by said locking means, means to turn said locking means into engagement with said locking member, the interengagement of said locking means'and locking member preventing turning of said shaft regardless of the axial position of the shaft.

9. In a switch as claimed in claim 8 wherein said locking means and locking member may occupy two different engaging positions on one of which said shaft is entirely immobilized.

10. In a switch as claimed in claim 9 wherein in the other of said two positions the shaft may be moved axially in one direction only from an intermediate position.

11. A switch as claimed in claim 8 wherein said locking means and locking member are formed to permit movement axially of saidshaft in one direction only from an intermediate position when said locking means and member are in one engaging position.

12. A switch as claimed in claim 11 wherein the locking means comprises a lever having a stepped lug which is engageable wholly or partially with the locking member on said shaft.

13. In a selector switch, a shaft movable rotatively and axially to operate difierent contacts, said shaft being movable axially from an intermediate into pushed and pulled positions, means upon which said shaft is mounted, interfitting means on said shaft and said mounting means preventing rotation of said shaft under certain conditions, said interfitting means being freed by axial movement of said shaft in one direction from intermediate position, said shaft being turnable when said interfitting means are freed, in combination with locking means turnable about a fixed pivot, a locking member ailixed to said shaft interengageable by said locking means, means to turn said locking means into engagement with said locking member, the interengagement of said locking means and locking member preventing turning of said shaft regardless of the axial position of the shaft, said locking means and locking member being engageable in two different positions in one of which said shaft is entirely immobilized in an axial position other than the intermediate axial position.

14. A switch as claimed in claim 13 wherein the locking means comprises, a lever having a stepped lug which has its end face in engage ment with said locking member in said one immobilizing position.

DAVID W. JOHNSON.

REFERENCES CITED The following references are of record in the nle of this patent:

UNITED STATES PATENTS Number 

